Narrative:

I was a required crew member during a crash fire rescue equipment 14 part 91 flight from ads to ams in aircraft X (a hawker HS125-700) aircraft operated by our company on sep/xa/00. The flight was on an IFR flight plan transition. Takeoff was conducted normally and initial altitude and heading assignments were an immediate left turn to heading 100 degrees, and initial climb to 2000 ft MSL. We were to receive vectors for the assigned departure procedure. We were subsequently assigned a sbound heading and assigned a higher altitude of 8000 ft MSL, after which we were handed off to the next TRACON controller. Shortly after the handoff, this controller instructed us to climb and maintain 13000 ft MSL. The PNF read back the altitude assignment, looked at me and said climb to 13000 ft MSL and set that altitude in our altitude selector. The controller did not acknowledge. We began our ascent to 13000 ft MSL, after confirming to each other and the controller that 13000 ft MSL was the assigned altitude. Upon passing 11500 ft MSL, the controller advised us that he believed to have only cleared us to 10000 ft MSL. We were instructed to expedite our climb to 13000 ft MSL to resolve an impending traffic conflict with air carrier Y, an F100. We complied quickly and traffic passed below us with 1000 ft separation. We told the controller during our climb to 13000 ft that we were assigned 13000 ft MSL. The controller did not reply. Shortly thereafter, we were handed off to ZFW, and no further mention of the incident was made to us. The flight proceeded to destination uneventfully. That morning, the controller appeared busy and did not correct himself for his erroneous altitude assignment when we read it back to him. The flight crew performed all tasks with proper execution of CRM. The controller could have avoided the whole incident if he had paid attention to pilot readbacks of altitude assignments.

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Original NASA ASRS Text

Title: PLT DEPARTING DFW IN HS125 BELIEVES THE DEP CTLR MAY HAVE INADVERTENTLY ISSUED AN INCORRECT ALT.

Narrative: I WAS A REQUIRED CREW MEMBER DURING A CFR 14 PART 91 FLT FROM ADS TO AMS IN ACFT X (A HAWKER HS125-700) ACFT OPERATED BY OUR COMPANY ON SEP/XA/00. THE FLT WAS ON AN IFR FLT PLAN TRANSITION. TKOF WAS CONDUCTED NORMALLY AND INITIAL ALT AND HDG ASSIGNMENTS WERE AN IMMEDIATE L TURN TO HDG 100 DEGS, AND INITIAL CLB TO 2000 FT MSL. WE WERE TO RECEIVE VECTORS FOR THE ASSIGNED DEP PROC. WE WERE SUBSEQUENTLY ASSIGNED A SBOUND HDG AND ASSIGNED A HIGHER ALT OF 8000 FT MSL, AFTER WHICH WE WERE HANDED OFF TO THE NEXT TRACON CTLR. SHORTLY AFTER THE HDOF, THIS CTLR INSTRUCTED US TO CLB AND MAINTAIN 13000 FT MSL. THE PNF READ BACK THE ALT ASSIGNMENT, LOOKED AT ME AND SAID CLB TO 13000 FT MSL AND SET THAT ALT IN OUR ALT SELECTOR. THE CTLR DID NOT ACKNOWLEDGE. WE BEGAN OUR ASCENT TO 13000 FT MSL, AFTER CONFIRMING TO EACH OTHER AND THE CTLR THAT 13000 FT MSL WAS THE ASSIGNED ALT. UPON PASSING 11500 FT MSL, THE CTLR ADVISED US THAT HE BELIEVED TO HAVE ONLY CLRED US TO 10000 FT MSL. WE WERE INSTRUCTED TO EXPEDITE OUR CLB TO 13000 FT MSL TO RESOLVE AN IMPENDING TFC CONFLICT WITH ACR Y, AN F100. WE COMPLIED QUICKLY AND TFC PASSED BELOW US WITH 1000 FT SEPARATION. WE TOLD THE CTLR DURING OUR CLB TO 13000 FT THAT WE WERE ASSIGNED 13000 FT MSL. THE CTLR DID NOT REPLY. SHORTLY THEREAFTER, WE WERE HANDED OFF TO ZFW, AND NO FURTHER MENTION OF THE INCIDENT WAS MADE TO US. THE FLT PROCEEDED TO DEST UNEVENTFULLY. THAT MORNING, THE CTLR APPEARED BUSY AND DID NOT CORRECT HIMSELF FOR HIS ERRONEOUS ALT ASSIGNMENT WHEN WE READ IT BACK TO HIM. THE FLC PERFORMED ALL TASKS WITH PROPER EXECUTION OF CRM. THE CTLR COULD HAVE AVOIDED THE WHOLE INCIDENT IF HE HAD PAID ATTN TO PLT READBACKS OF ALT ASSIGNMENTS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.